The police officer who threatened to arrest Victor M. Rios for conspiracy would have been hard-pressed to make a charge stick. At the time, all Rios was doing was hanging out with teenagers on some of the country's toughest streets, in Oakland, Calif.

As a doctoral candidate in ethnic studies at the University of California at Berkeley, Rios spent three years shadowing 40 youths between the ages of 14 and 17, a lot of whom had arrest records and gang affiliations. He had plenty of opportunity to learn that many police officers had a poor opinion of any efforts to understand inner-city youths. The police were instead part of a system that kept the boys under constant surveillance, criminalized their even relatively benign behavior, and left them demoralized and angry, Rios argues in a new book, Punished: Policing the Lives of Black and Latino Boys (New York University Press).

When police officers demanded to know what he was doing, Rios knew the routine: Be deferential, even when abusively spoken to. He had grown up on those Oakland streets and he knew the costs of stepping out of line. One day, when he was 14, an officer "stomped my face against the ground with his thick, black, military-grade rubber boot," he writes.

Rios, now an assistant professor of sociology at the University of California at Santa Barbara, was no angel when that happened. He had just been pulled over in a car he had stolen. He had joined a gang at 13, lured by the promise of protection in Oakland's drug-riddled, gang-controlled neighborhoods. Soon he was dealing drugs. He was witnessing beatings, knifings, and murders. He served a string of juvenile-detention sentences. And he would soon see his best friend, Smiley, killed by a rival gang member, a bullet to his head.

How Rios, now 33, came to escape that life, and earn a Ph.D., is one striking narrative in Punished. Another is his account of the dissertation research that took him back to the neighborhoods where he grew up. Starting in 2002, he wandered the streets with his subjects at all times of day and night. He saw the jeopardy that defined their lives. And he met their families, their probation officers, and the police officers who constantly monitored them. The boys' encounters with the police were almost always negative.

With Punished, Rios joins an expanding cadre of social scientists who lament the directions that juvenile justice has taken in the United States in recent decades. He argues that in an era when the United States has achieved world-record levels of incarceration, of young people as well as adults, the widespread adoption of severe, hastily adopted get-tough-on-crime policies in the 1980s and 1990s has gone hand in hand with the vilification and persecution of black and Latino youths.

Rios witnessed rogue officers, along with overwhelmed school officials, hustle countless youths down a steep decline into the criminal-justice system. Authority figures harassed or demeaned the boys, often merely because they were presumed to be bad based on their racial or ethnic identity. Police often beat youths as young as 12 and falsely branded many as gang members, a dire development in California where an individual's inclusion on a statewide gang database frequently leads to prosecution as an adult and lengthened prison sentences.

A lot of police officers "seemed to sympathize with the poverty and trauma that many young people experienced," Rios writes. "However, in an attempt to uphold the law and maintain order, officers often took extreme punitive measures with youths perceived as deviant or criminal." He calls this a "paradox of control."

Often no amount of empathy could have stemmed the youths' own contributions to their unhappy fates. Rios observed their brutal infighting and the criminality of many young men. (In his book, he concentrates on boys, to whom he had the best access, but he notes that several studies of inner-city girls have appeared in the last few years, too.) In the boys' world, he says, "instead of feeling that you can graduate high school and go to college as a coming-of-age ritual, now you might grow up thinking that in order to show your manhood, you have to get locked up."

But Rios also notes the youths' ingenuity under bleak circumstances, their resilience, and their often-thwarted efforts to lead good lives.

*****

Rios relates more of his own story in Street Life: Poverty, Gangs, and a Ph.D., a short, self-published biography he gives to young men he encounters, hoping to inspire them to overcome their disadvantages the way he has done. It is an astonishing account of hardship and deliverance by education.

The son of a Mexican immigrant mother, Rios grew up in crowded, roach-infested housing where rats the size of small cats gnawed through ceilings and dropped on Rios's bed, and one landlord's remedy for break-ins by thieving junkies was to board up the apartment's windows, he writes. Then, Rios's family lived in a cavelike hovel where the electricity was often turned off. Neglected and bullied, Rios stopped going to school, instead taking lessons from older boys in how to steal cars. But he got lucky. When he was 16, a police officer who arrested him for fighting a gang rival in front of a high school kindly teased Rios's life story from him and told him he had better turn his life around.

Rios did, with the help of a teacher at the school from which he had long been truant. Earlier, after spotting his potential, she had told him to come back to school any time. With her help, he raised his grade-point average and was able to enroll at California State University-East Bay in a probationary program. He earned a bachelor's degree while working full time and living in a small, barely habitable house with three family members. He then rapidly progressed to a doctorate at Berkeley, earning it within five years, at the age of 26, even though he became a father of twin girls early in his enrollment.

At the beginning of Rios's field work, a professor cautioned him not to "go native." But he could hardly shed his gang savvy. Even though he was "always, always concerned about safety, always in precarious predicaments," he says, "I kind of knew how to prevent myself from getting caught up in very vulnerable situations." He dressed like his baggy-pantsed subjects, and revived the aloof bearing of his own youth. Aware of his gangbanger past, his subjects referred to him as "O.G. [Original Gangster] Vic."

Still, he often ignored his own keen sense for danger: "I got caught in many of those moments where I wasn't a researcher, I wasn't a grad student, I wasn't a family man who needed to stay alive so I could be there for my children at the end of the day." When, for example, one of his subjects ruthlessly attacked another boy, kicking him on the ground, "that's when I stepped in," says Rios. "I got this kind of tunnel vision, that I just needed to do this, because it's my obligation."

Pausing a moment, he continues: "As it happens, some of the boys did get, you know, injured or killed, being out at night."

Today, as Rios skateboards around campus to minimize down time, bearded and in shades, it is hard to distinguish him from a graduate student. Nothing about his appearance (no obvious tattoos, for example) identifies him as ever having been a gang member. He repeatedly registers his relish for sunny Santa Barbara and the University of California campus with its palm-framed views of the Pacific Ocean.

His hale appearance is something he had to regain after conducting his exhausting fieldwork, he says: "It had a deep impact on my psyche during that time. I remember being real stressed. I felt depressed, really unhealthy."

Over lunch at the beachside faculty club on the Santa Barbara campus, where a whole academic lifetime seems indisputably safer than one day in gang territory, he says: "A great research question would be: Why not more violence? Why aren't these kids attacking everyday people? Why are they only attacking themselves?" Knowing the answers, "we might get a little closer to finding ways to implement policies that will allow communities to bring in their own controls relating to group violence."

In fact, he says, "I saw good people who were constantly struggling to remain good, to keep their morals, their values, their positive norms intact despite the crazy environment that was telling them otherwise." He saw even broken families provide sound guidance to their children: "One of the kids I saw who started to change his life around, and started attending college, his father was in prison, and his mother had drug problems. He said, 'Man, when I was a little kid, my dad would show up, and I would run up and hang on his big, giant hand, and he would always teach me, 'You've got to be a hard worker.'"

But being treated as pariahs scarred almost all the children he observed, even the smartest and best-behaved, he says. "They had to overcompensate to prove they were really not criminals," he says. Rejecting negative characterizations often led to rejecting family members and neighbors who had been similarly labeled. Rios, indignant, exclaims: "These young people are children, and we've failed them, as adults, as grown-ups, as professionals. We've failed them as a society."

At least, he says, the forces that marginalize such youths kindle resistance in some: "These are the kids that then become activists, who may go on to college, and become attorneys and fight for the rights of their communities."

*****

Rios's book adds an insider's view to the growing body of research on juvenile justice. The vast majority of current researchers' views could hardly differ more from those of the conservative policy makers and academics who, from the 1970s to the 1990s, advocated successfully for "zero tolerance," "the war on drugs," and "three-strikes" laws. Relying on the "broken windows" theory of how neighborhoods deteriorate, they encouraged the police to police crack down on misdemeanors to discourage more-serious crime. And they warned that inner-city "moral poverty" would lead to the rise of sociopathic "superpredators."

News-media outlets chimed in by framing dire urban problems as somehow predominantly a threat to suburbanites. Cast as dangerous and incorrigible, large sections of the American population came to seem fit for nothing but incarceration—even though serious-crime rates had been falling.

In the late 80s and 90s, school shootings magnified the specter of youth violence and ushered in the stringent school policing that exists today, says Meda Chesney-Lind, a professor of women's studies at the University of Hawaii-Manoa. Particularly in minority communities, schools "have been turned into medium-security prisons" with metal detectors, backpack searches, pat downs, and criminalizing of "extremely minor forms of violence," she says. No wonder, she adds, that "if you have situations in schools that are tantamount to educational neglect, where kids feel invisible or worse, policed, and criminalized, then they're angry."

They express that anger, writes L. Janelle Dance in her book, Tough Fronts: The Impact of Street Culture on Schooling (Routledge, 2002), with "gangster" demeanor, dress, and mannerisms, even at the risk of appearing to be "troublemakers." Dance is an associate professor of sociology at the University of Nebraska at Lincoln.

With zero-tolerance policing have come the long and mandatory sentences that remove judicial discretion and prosecute juveniles as adults. Criminologists differ on the efficacy of such measures in deterring youths who are considered threats to public order. Many researchers favor maintaining stringent policing; but virtually all seem to believe that the side effects of mass incarceration, such as the impact on spouses and children left behind, signal a failed approach to juvenile justice.

Rios is no advocate of soft sentencing, not when so many family members and friends have been victims; nor are the many other social scientists who assert that punishments should better fit crimes. Still, when Rios discusses that issue, his perspective is decidedly not middle America's. For instance, he expresses shock that a young offender may receive a 15-year prison sentence for stabbing a rival, even though the victim does not die. His perspective is shaped by seeing the realities of life on those Oakland streets, where many young men go to prison for merely being somehow associated with someone who carried or fired a gun.

Many specialists in juvenile justice say they admire what Rios has achieved in Punished: to show, from his unusual perspective, how inner-city Latino and African-American boys develop their sense of self in the midst of crime and intense policing, and how it can come about that young minority men lose trust in the institutions of civil society.

To date, says Paul Hirschfield, an associate professor of sociology at Rutgers University, research has focused narrowly on whether stringent modern-day policing of young Americans actually reduces crime or increases it—a vexing and complex question. "But that's not the only outcome," he says. "What about children's perceptions of authority? If these kids come to view government, from police to teachers, as oppressive, and as unresponsive to their needs, how likely are they to trust in government going forward? And their eroding trust in government and their declining civil engagement are damaging to democracy itself."

Colleagues also say Rios has provided valuable details needed to gauge the impact of severely punitive policing on communities. John M. Hagedorn, an associate professor of criminal justice at the University of Illinois at Chicago, says that Rios looks beyond the tired paradigms of "social disorganization, leading to weakened roots and loss of control" that have mired that analysis.

What are still needed, say juvenile-justice experts, are better answers to difficult questions: What really explains why arrests for minor offenses have not dropped, even though serious crime has? Have police shifted their attention to minor offenses to fulfill an institutional mandate to make more minor arrests? Hirschfield, of Rutgers, suggests: "The more pressure they're under to show they're doing something, the more arrests they are going to make. The more pressure they're under to show it's working, the fewer serious crimes they're going to record."

Indeed, Rios notes, inner-city residents commonly assume that police will ignore their calls for help and will hinder rapid response from emergency services. If not for such delays, he says, his childhood friend Smiley might have survived being shot.

Hagedorn believes the role of state agents in fostering crime warrants closer inspection. "As long as the problem is, What's the matter with these kids?—whether it's loose morals, or unemployment, or bad schools, or not enough discipline—we're focused on the kids, and we leave out the political structures and the structures of a city that facilitate that. You don't have this drug economy raging without cooperation in major ways from police and local officials."

Still, Rios believes policy makers should not wait until all the data are in but put in place partial remedies now, like the "democratic schools" advocated by Aaron Kupchik, an associate professor of sociology and criminal justice at the University of Delaware. Kupchik says: "One of the primary things we know works to prevent violence and crime isn't policing or zero tolerance; it's having democratic schools, where kids feel valued, respected, and a part of the school." One by one, schools can be reformed, and police departments can train officers better in how to interact with minority youth.

As Rios sees things, institutional reform is urgently needed, but so too is mentoring by individuals who know what it is like to grow up poor in inner cities. The winner last year of a University of California at Santa Barbara award for excellence in mentoring undergraduate research, he has trained scores of his students in collecting data about the challenges local youths face. And he encourages students to turn their research groups into community-outreach groups.

On a recent Friday, he took several of his students to inner Santa Barbara's Casa de la Raza, a community center, to pick up as many Latino youths as they could, and ferry them off to a ballpark to play softball.

Between some committed running of base paths, chasing of fly balls, and turns on the pitching mound, Rios found time to wander to a corner of the field to tell a few youths that, if he could see them drinking beer, certainly any passing police officer would.

Streetwise, self-confident, and strong-willed, Rios may be at ease in the faculty club, but at the ball park he seemed to be among his own. That warning he got from the Berkeley professor against going native? This was Rios's response: "I took your advice and went native in the academy, but I made sure to go back to the community where I come from."